


practice

by supernormal



Series: Sengen gentle dom [8]
Category: Dr. STONE (Anime), Dr. STONE (Manga)
Genre: Bottom Ishigami Senkuu, M/M, Making Out, Plot What Plot/Porn Without Plot, Tooth-Rotting Fluff, Top Asagiri Gen, Trans Male Asagiri Gen, Trans Male Character, Vaginal Fingering, Vaginal Sex, has accompanying art in end note
Language: English
Status: Completed
Published: 2020-10-23
Updated: 2020-10-23
Packaged: 2021-03-09 05:01:00
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,625
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/27158311
Author URL: https://archiveofourown.org/users/supernormal/pseuds/supernormal
Summary: Gen asks Senku to make him cum all by himself, with (little to) no help.
Relationships: Asagiri Gen/Ishigami Senkuu
Series: Sengen gentle dom [8]
Series URL: https://archiveofourown.org/series/1726681
Comments: 2
Kudos: 51





	practice

**Author's Note:**

> context is that i was gonna write a little series of fics of gen giving awkward virgin senku sex “lessons” but I never really got around to it (tho I did kinda get started) here's a random thing that would have taken place pretty soon before they formally got together at the end of the series dnssjsjjsjs.

"Senku-chan, come here." Gen was sitting up on the futon and he was beckoning Senku to join him. Senku obediently put his things away and crawled down in front of him. Gen stroked his chin. "Are you ready for tonight?"

He nodded. Gen was already partially undressed; he was down to just his pants and undershirt that was unfastened just enough so that it showed a hint of cleavage. They hadn't even gotten started but Senku already felt his blood rushing to his dick. When he imagined reaching out to slip his hands under his garment to feel him up, he felt all hot.

"Okay, Senku-chan, today you're gonna make me cum by yourself. I won't touch myself or anything, so you're going to do all the work. Understand?"

He rubbed the back of his neck, having just snapped out of his little daydream. "Yeah."

"Mhm. Good boy. And I’m gonna cum first today, okay? So hold it in until I give you permission.”

Senku gulped. He was usually the one to cum first, sometimes way too soon, but he was up for the challenge. He eyed the space between Gen’s legs, unsure of how to proceed.

Gen slid off his pants and spread his legs. "Come closer, don't be shy." Senku crawled closer, so close that their noses touched. "What're you gonna do?"

"Um…" He gingerly placed his fingers on his vulva. It was already pleasantly wet. "F… Finger you?"

He smiled. "Good. Don't hesitate." Senku pressed his fingers down and began to steadily rub the outside. Gen was getting wetter by the minute the longer Senku worked his fingers. "Aha… Good boy," he breathed, "See, you know what you're doing, right?"

"Y-Yeah…" he teased his index finger around his hole, and Gen bucked his hips forward in pleasure. "Hey…" He slowly leaned in and softly kissed him on the lips. Gen kissed him back, and Senku could feel him smiling against his face. That made him a bit nervous, and he tried to kiss him harder, sticking out his tongue and licking around his mouth and chin, trying to get back at him in a way and to coax his mouth open.

"Hehe, Senku-chan… what are you…"

Senku furrowed his brow and probed his tongue into his mouth, just a little. He leaned over him a bit more aggressively, pushing him back a bit, ready to have him on his back.

_"Mm…"_

He gingerly kissed him back as Senku clumsily worked his tongue into his mouth. Gen was still smiling and almost giggling occasionally, which kind of irked him.

_Take me seriously, dammit._

Down there, Senku was ready to insert the first finger; he had been rubbing the outside long enough that Gen was wet and loose enough to take something inside. Senku didn't stop kissing him as he stuck in the first joint of his finger, then the second, then the third.

Gen quietly gasped against his lips and scrunched up the leather of his dress in his fists to hold on. Senku was pleased at his subtle show of submission, and he moved his index finger around inside while feeling up the entrance with the next finger, his middle.

Senku wasn't sure how long it would take to get used to the warm, smooth wetness of gens vagina. It was still so foreign, but it was something he for sure could get addicted to.

Gen was already enjoying it, though. _"Mm… you're doing really well,"_ he murmured. He slung both his arms around Senku's shoulders.

He plunged his fingers in and out, occasionally rubbing his clit and earning a stifled moan or squeak from his partner. He could feel the clothes around his crotch tighten. He didn't know how much longer he could last before joining in himself.

_"I, I think I'm gonna cum in a bit,"_ whispered Gen. Senku looked down at his flushed red face. He was already sweating and panting, and each moan he let out turned him on even more.

_Fuck, I can't let him have all the fun…_

He abruptly pulled his fingers out and moved his hand to his belt.

"Huh?" Gen looked up at him, confused, but also drearily aware of what was going to happen.

"H-Hold on," he stuttered as he fumbled with his belt, doing his best to open the front of his skirt with one hand. When he managed to undo the fasteners, his hard cock sprang out, precum already leaking.

"Oh… You want to…" His voice was low.

"I need it too, you know." He gently touched the smooth, pale skin of his inner thighs. "Spread your legs more for me."

Gen was already out of breath but he grabbed his legs and pried them open the best he could, presenting to him his most intimate parts.

“That's good…” Senku crouched over him and positioned the head right onto the entrance, wasting no time. He moved it up and down his vulva a couple times, both for pleasure and to lubricate it just a bit more. _"I'm gonna go in now."_ He tilted his hips and effortlessly slid it in. Gen sharply gasped, eyes widened. 

_"F-fuck!_ Senku-chan!”

The warm, wet insides of his vagina were gripping him already, and he wasn't even all the way in yet. He smoothly inserted himself the rest of the way, sighing in pleasure.

_“Nnh!”_ Gen held onto him as tight as he could. “So deep!”

_“God, you feel so fucking good,”_ he breathed. He pulled his cock out right to the tip and then slammed it back in, all in one go. Gen squealed in pleasure and locked his legs around Senku’s hips. Senku started to slowly, steadily pump in and out, doing his best to prolong both of their pleasures before the inevitable climax.

“S-Senku-chan… Come here.” Gen pulled him downward and passionately kissed him on the lips, while tightening his legs’ hold on him. Senku didn't stop moving his hips, though they stuttered and slowed down a bit while he was focused on tending to Gen’s neediness.

A soft moan into Senku’s mouth accentuated the apex of each thrust. Senku could tell that he was already close to cummimg, so he slowed down, instead opting for steadier but also stronger movements. Neither of them were going to last very long today, but Senku wanted to show off the confidence he had gained over the course of Gen’s little “lessons”.

He set a steady pace for himself, pistoning his hips in and out, in and out. Gen looked like he was having a lot of fun under him. He was cooing encouragement at him, _good boy_ s and _you’re so good_ s.

Shit. He felt that familiar heat coiling up inside his groin and knew he was close, but he used every bit of strength in him to hold on until Gen orgasmed first like he ordered him to.

Luckily, Gen was already there.

_“Cumming!”_ He arched his back and convulsed in ecstacy, dragging his nails across Senku’s back. The way that his pussy squeezed around Senku’s cock made it feel like he was deliberately milking the cum out of him, but Senku held on with all his willpower, waiting for Gen to come down from his high so that he could pull out and finish all over his stomach. Each movement of his hips made him want to burst, though. He grit his teeth and kept moving his hips through it all, wanting to please Gen and earn his praise more than anything.

After a bit Gen calmed down and relaxed fully. He smiled tiredly. “I can see you're ready too, Senku-chan,” he whispered. “You have my permission to cum.”

Before he had even finished his sentence Senku had pulled out and was feverishly jerking himself off, aiming right at Gen’s midriff, panting heavily. It didn't take long for his cum to shoot out and splatter all over his stomach. He couldn't hold back his groans as he unloaded his warm seed. Fuck, he was so tired but it felt _so good._

Gen cooed praise at him, showing him in “good boy”s and telling him how far he’s come, and how well he did tonight. He had so much in him that his semen was pooling into Gen’s belly button and spilling onto the futon, but neither of them cared too much. When Senku was sure his balls were drained he slumped back, exhausted. A lot had come out.

Gen reached out to caress his cheek. “Hey.”

He instinctively leaned his face into his palm. Gen always lovingly caressed his face when they finished, and Senku was accepting his touch almost unconsciously now.

“You did so good. You've come so far from the first time, remember?”

“Yeah…” He scowled a bit after remembering how clumsy he was.

Gen moved his hand to the back of his head to pull him towards him. “Kiss me again.”

They were both messy and covered in sweat and Gen still had a puddle of Senku’s cum on his stomach but they kissed as tenderly as before. Gen lovingly ran his fingers through Senku’s hair; he had a habit of doing that when they kissed.

Senku pulled away after a few moments and looked down. “Um, we should probably clean you up before we go to bed or anything.”

“That would be a good idea.”

He retrieved a damp cloth and wiped off his stomach. Gen pulled his pants back up and took out a blanket. After they both cleaned themselves up a little more, they settled down under the covers together, Gen holding Senku to his chest.

“Goodnight, my darling Senku-chan.”

Senku felt his face heat up a little at the added-on _my darling._

“...'Night.”

**Author's Note:**

> [here's drawing lol (pic is explicit of course)](https://media.discordapp.net/attachments/746359620918050879/769048738173812766/more_porn_aaaa.png?width=772&height=677)
> 
> I fell off the face of the Earth because I'm busy with college and it's kinda hard to get around to writing full-fledged fics rn. i post art (and bits of writing) waaaaay more often on my twitter, [you can request to follow here](https://twitter.com/foggytrees)


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